BGE Mouse Look Min and Max Bounds Changing?
You should use the actuator.angle attribute, or actuator.angle[0] if only the X value is needed. Here's a example script I made and test file attached here.

import bge

from bge.logic import expandPath
from ast import literal_eval

def main(cont):

    # Objects
    own = cont.owner

    # Sensors
    S = cont.sensors['S']
    L = cont.sensors['L']

    # Actuators
    MLook = own.actuators['MLook']

    # Properties
    path = expandPath('//save.txt')

    data = {
        'pos' : list(own.worldPosition),
        'rot' : list(own.localOrientation.to_euler()),
        'mouse' : MLook.angle
        }

    ### PROCESSING ###
    # Save
    if S.positive:

        with open(path, 'w') as opened_file:
            opened_file.write(str(data))
            print('Saved data to', opened_file.name)

    # Load  
    if L.positive:

        try:
            with open(path, 'r') as opened_file:
                data = literal_eval(opened_file.read())
                print('Saved data to', opened_file.name)

            # Set obj data
            own.worldPosition = data['pos']
            own.localOrientation = data['rot']
            MLook.angle = data['mouse']

        except:
            print('Cant load saved file')